Due to the prevalence of digital cameras in modern society, and the ease with which such images can be distributed and shared through media such as the Internet, there is an extremely large and ever growing collection of images containing faces available for consumption by the public. Moreover, private collections of images containing faces are also being compiled at ever increasing rates as the number of devices capable of collecting such images that are owned and used by individuals continues to increase.
However, the ability to search these public and private collections of images containing faces has been limited due to a lack of classification of the images. While some images have been classified to describe what is contained in the faces in such images, prior classification attempts have been inadequate. For example, manual classification of images is time consuming and thus expensive, prior automatic classification has been frequently inaccurate because it tends to rely on text surrounding an image for classification, not on the image itself, and the remaining images (which constitutes the vast majority of images) are simply not classified at all.